As I wrote yesterday, I’m currently hacking on libopencm3 for bare-metal Vybrid development. This effort advanced quite a bit, the GitHub repository now contains code to use the UART and GPIOs from the Cortex-M4.
The Hardware I use consists of a Toradex Colibri VF61 on a Iris Carrier Board. The code should also run fine on Freescales Vybrid Tower board (TWR-VF65GS10). Currently I use the preinstalled Linux BSP consisting of U-Boot, Linux 3.0 Kernel and a OpenEmbedded based root file system.